Efficacy, Safety, and Tolerability of Eluxadoline in the Treatment of Participants With Diarrhea-Predominant Irritable Bowel Syndrome (IBS-d)

Inclusion Criteria:

1. Participant is 18 to 80 years old

2. Participant has a diagnosis of irritable bowel syndrome (IBS) with a subtype ofdiarrhea defined by the Rome III criteria.

3. Participant has had a colonoscopy performed:

• Within 10 years prior to Prescreening if participant is at least 50 years of age (sigmoidoscopy, double contrast barium enema, or computed tomography (CT) colonographywithin the past 5 years is acceptable)

• Since the onset (if applicable) of any of the following alarm features forparticipants of any age

• Participant has documented weight loss within the past 6 months

• Participant has nocturnal symptoms

• Participant has a familial history of first-degree relatives with colon cancer

• Participant has blood mixed with their stool (excluding blood from hemorrhoids).

3. Female participants must be:

• Postmenopausal, defined as 52 years or older and amenorrheic for at least 2 years atPrescreening,

• Surgically sterile (have had a hysterectomy or bilateral oophorectomy, tubal ligation,or otherwise be incapable of pregnancy),

• Abstinent, or

• If sexually active, be practicing an effective method of birth control.

Exclusion Criteria:

1. Participant has a diagnosis of IBS with a subtype of constipation, mixed IBS, orunsubtyped IBS by the Rome III criteria.

2. Participant has a history of inflammatory or immune-mediated gastrointestinal (GI)disorders including inflammatory bowel disease (ie, Crohn's disease, ulcerativecolitis) and celiac disease.

3. Participant has a history of diverticulitis within 3 months prior to Prescreening.

4. Participant has a history of intestinal obstruction, stricture, toxic megacolon, GIperforation, fecal impaction, gastric banding, bariatric surgery, adhesions, ischemiccolitis, or impaired intestinal circulation (eg, aortoiliac disease).

5. Participant has any of the following surgical history:

• Cholecystectomy with any history of post cholecystectomy biliary tract pain

• Any abdominal surgery within the 3 months prior to Prescreening

• Participant has a history of major gastric, hepatic, pancreatic, or intestinalsurgery (appendectomy, hemorrhoidectomy, or polypectomy greater than 3 monthspost surgery are allowed) Other protocol-specific eligibility criteria may apply.